Download Parts of the skeletal system

5
The Skeletal System
PART A
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALS
OF HUMAN
ANATOMY
& PHYSIOLOGY
EIGHTH EDITION
ELAINE N. MARIEB
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
The Skeletal System
 Parts of the skeletal system: bones, joints,
cartilages, and ligaments
Function of bones:
 Support body, protects organs, allows
movement, storage of minerals & fats, blood
cell formation
Divided into two divisions
 Axial skeleton (skull, vertebrae, thorax)
 Appendicular skeleton (limbs, pectoral
and pelvic girdles)
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Bones of the Human Body
 The adult skeleton has 206 bones
 Two basic types of bone tissue
 Compact bone: hard, solid
 Homogeneous
 Spongy bone
 Small needle-like
pieces of bone
 Many open spaces
Figure 5.2b
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Classification of Bones on the Basis of
Shape
Figure 5.1
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Gross Anatomy of a Long Bone
 Diaphysis
 Shaft, compact bone
 Compact bone
 Epiphysis
 Ends of the bone
 Mostly spongy bone
 Articular Cartilage
 Covers surface of ends
 Hyaline cartilage
 Reduces friction
Figure 5.2a
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Structures of a Long Bone
 Periosteum: Outside covering
of diaphysis
 Fibrous connective tissue
 Sharpey’s fibers: Secure
periosteum to underlying bone
 Arteries: Supply bone cells
with nutrients
 Medullary cavity: Contains
yellow marrow (mostly fat)
in adults, red marrow (blood
cell formation) in infants
Figure 5.2c
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Bone Markings
Bone Markings
 Sites of attachments for muscles, tendons, and
ligaments
 Passages for nerves and blood vessels
 Bone markings:
 Projections and processes – grow out
from the bone surface, bumps, mounds
 Depressions or cavities – indentations
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Microscopic Anatomy of Bone
Microscopic Anatomy of Bone
 Lacunae
 Cavities containing bone
cells (osteocytes)
 Arranged in rings
 Lamellae
 Rings around central canal
 Sites of lacunae
 Canaliculi
 Tiny canals
 Form a transport system
Detail of Figure 5.3
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Changes in the Human Skeleton
 Embryo: skeleton is mostly hyaline cartilage
 This cartilage is eventually replaced by bone
 Cartilage remains in:
 Bridge of the nose
 Parts of ribs
 Joints
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Long Bone Formation and Growth
Figure 5.4a
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Types of Bone Cells
 Osteocytes
 Mature bone cells
 Osteoblasts
 Bone-forming cells
 Osteoclasts
 Bone-destroying cells
 Break down bone matrix for remodeling and
release of calcium
 Bone remodeling is a process by both osteoblasts
and osteoclasts
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Bone Fractures
 Types of bone fractures
 Closed (simple) fracture – broken bone
does not penetrate the skin
 Open (compound) fracture – penetrates
through the skin
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The Axial Skeleton
Axial Skeleton
 Forms the longitudinal part of the body
 Divided into three parts
 Skull
 Vertebral column
 Bony thorax
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The Axial Skeleton
Figure 5.6
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The Skull
Figure 5.7
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Bones of the Skull
Figure 5.11
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Paranasal Sinuses
Paranasal Sinuses
 Hollow portions of bones around nasal cavity
 Lightens skull, voice resonates
Figure 5.10
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The Fetal Skull
 The fetal skull is large
compared to body
 Fontanelles – fibrous
membranes connecting
the cranial bones (“soft
spots” of baby’s head)
 Allows brain
to grow
 Converts to bone
within 24 months
Figure 5.13
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The Vertebral Column
 Vertebrae separated by
intervertebral discs
 The spine has a normal
curvature
 Each vertebrae is given a name
according to its location
Figure 5.14
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The Bony Thorax
Bony Thorax
 Protects major
organs
 Three parts
 Sternum
 Ribs
 Thoracic
vertebrae
Figure 5.19a
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The Appendicular Skeleton
Appendicular Skeleton
 Limbs (appendages) – bones of arms, legs
 Pectoral girdle – bones of chest
 Clavicle – collarbone
 Scapula – shoulder blade
 Pelvic girdle – bones of pelvis
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Bones of the Shoulder Girdle
Figure 5.20a–b
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Bones of the Upper Limb
 The arm is formed by
 Humerus
 The forearm
 Ulna
 Radius
Figure 5.21a–b
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Bones of the Upper Limb
 The hand
 Carpals – wrist
 Metacarpals –
palm
 Phalanges –
fingers
Figure 5.22
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Bones of the Pelvic Girdle
Pelvic Girdle
 Hip bones, protect several organs
 Three pair of fused bones: Ilium, Ischium, Pubic bone
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Bones of the Lower Limbs
 Thigh bone:
Femur
 Lower leg:
 Tibia
 Fibula
Figure 5.24a–b
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Bones of the Lower Limbs
 The foot
 Tarsus – ankle
 Metatarsals – sole
 Phalanges – toes
Figure 5.25
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Structural Classification of Joints
Joints – hold bones together, allow mobility
 Fibrous joints
 Generally immovable
 Sutures of scull, holds tibia fibula together
 Cartilaginous joints
 Immovable or slightly moveable
 Pubic symphysis; between vertebra
 Synovial joints
 Freely moveable
 Shoulder, elbow, wrists
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Inflammatory Conditions Associated with
Joints
 Bursitis – inflammation of a bursa usually
caused by a blow or friction
 Tendonitis – inflammation of tendon sheaths
 Arthritis – inflammatory or degenerative
diseases of joints
 Over 100 different types
 The most widespread crippling disease in
the US
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